Book Image

Puppet 5 Essentials - Third Edition

By : Felix Frank
Book Image

Puppet 5 Essentials - Third Edition

By: Felix Frank

Overview of this book

Puppet is a configuration management tool that allows you to automate all your IT configurations, giving you control over what you do to each Puppet Agent in a network, and when and how you do it. In this age of digital delivery and ubiquitous Internet presence, it's becoming increasingly important to implement scaleable and portable solutions, not only in terms of software, but also the system that runs it. This book gets you started quickly with Puppet and its tools in the right way. It highlights improvements in Puppet and provides solutions for upgrading. It starts with a quick introduction to Puppet in order to quickly get your IT automation platform in place. Then you learn about the Puppet Agent and its installation and configuration along with Puppet Server and its scaling options. The book adopts an innovative structure and approach, and Puppet is explained with flexible use cases that empower you to manage complex infrastructures easily. Finally, the book will take readers through Puppet and its companion tools such as Facter, Hiera, and R10k and how to make use of tool chains.
Table of Contents (10 chapters)

Using virtual resources

The next technique that we are going to discuss helps you solve conflicts in your manifests and build some elegant solutions in special situations.

Remember the uniqueness constraint that was introduced in Chapter 1, Writing Your First Manifests, any resource must be declared at most once in a manifest. There cannot be two classes or defined type instances that declare the same file, package, or any other type of resource. Each resource must have a unique type/name combination. This applies to instances of defined types as well as native resources.

This can pose issues when multiple modules need a common resource, such as an installed package, or perhaps even independent settings in the same configuration file. A component class for such resources, as introduced in Chapter 4, Combining Resources in Classes and Defined Types, will resolve basic conflicts...